Which sentence would you use more, which is just simple wrong and why?
This is the speech, that my father wrote.
This is the speech, which my father wrote.
This is the speech, what my father wrote.
...

Which would be best / acceptable?
"He saw people, animals and buildings THAT / WHICH had suffered greatly."
As I see it, there are 3 subjects; people, animals and buildings. The grammar rules I know ...

1) Eventually, we developed a strategy, grounded in prospect theory and its associated biases like loss-aversion and availability heuristic, which exploited the tendencies of players to fold too often ...